D5/d5a df-42 integrated exit cone and splash plate

ABSTRACT

A combustor basket assembly for a gas turbine engine that includes a combustor basket having a basket liner including an input end and an output end. An integrated exit cone and splash plate member is affixed to the output end of the basket liner and includes a base portion, an exit cone portion and a splash plate portion. The base portion includes an annular cooling channel that receives a cooling air flow and the exit cone portion and the splash plate portion each include an array of cooling feed holes in fluid communication with the cooling channel. The spacing between the feed holes and the size of the feed holes can be optimized to provide more cooling for hotter regions.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates generally to an integrated exit cone and splashplate member affixed to an output end of a combustion basket in a gasturbine engine and, more particularly, to a combustion basket assemblyfor a gas turbine engine, where the assembly includes an integrated exitcone and splash plate member affixed to an output end of a combustionbasket, and where the member includes an exit cone portion and a splashplate portion each having an array of cooling channels.

Discussion of the Related Art

The world's energy needs continue to rise which provides a demand forreliable, affordable, efficient and environmentally-compatible powergeneration. A gas turbine engine is one known machine that providesefficient power, and often has application for an electric generator ina power plant, or engines in an aircraft or a ship. A typical gasturbine engine includes a compressor section, a combustion section and aturbine section. The compressor section provides a compressed airflow tothe combustion section where the air is mixed with a fuel, such asnatural gas. The combustion section includes a plurality ofcircumferentially disposed combustors that receive the fuel to be mixedwith the air and ignited to generate a working gas. The working gasexpands through the turbine section and is directed across rows ofblades therein by associated vanes. As the working gas passes throughthe turbine section, it causes the blades to rotate, which in turncauses a shaft to rotate, thereby providing mechanical work.

The temperature of the working gas is tightly controlled so that it doesnot exceed some predetermined temperature for a particular turbineengine design because too high of a temperature can damage various partsand components in the turbine section of the engine. However, it isdesirable to cause the temperature of the working gas to be as high aspossible because the higher the temperature of the working gas, thefaster the flow of the gas because of the higher energy of the workinggas through the turbine engine, which results in a more efficientoperation of the engine.

In certain gas engine turbine designs, a portion of the compressedairflow is also used to provide cooling for certain components in thecombustion section and the turbine section, such as the vanes, bladesand ring segments. The more efficient cooling, where more efficientcooling maintains temperature with less cooling air, that can beprovided to these and other components allows the components to bemaintained at a lower temperature, and thus the higher the temperaturethe working gas can be, where more leakage decreases engine power. Forexample, by reducing the temperature of the compressed air, lesscompressed air is required to maintain the part at the desiredtemperature, resulting in a higher working gas temperature, lower airleakage, more mass flow through the engine for power extraction and agreater power and efficiency from the engine. Further, by using lesscooling air at one location in the turbine section, more cooling air canbe used at another location in the turbine section. In one known gasturbine engine design, 80% of the compressed airflow is mixed with thefuel to provide the working gas and 20% of the compressed airflow isused to cool engine parts.

In one known gas turbine engine design, a combustor basket is providedin each combustor of the engine, where the fuel and air are mixed andignited to generate a hot working gas. The hot working gas from thecombustor basket flows into a transition component and is directed tothe first row of vanes in the engine. It has been shown that some of thehot working gas that exits the combustor basket enters a recirculationzone as a result of a combustor basket exit cone, where the gases flowupstream in a direction towards the exit of the combustor basket, whichsometimes causes burning of a downstream surface of the exit cone and abasket liner. It is known in the art to add a splash plate to the basketliner at the end of the combustion basket that prevents the hot workinggas from directly impinging and burning the basket liner. The splashplate provides backside cooling for both the inner diameter surface andouter diameter surface of the basket, which allows both surfaces to becoated with a thermal barrier coating. Cooling flow is provided to thebackside surface of the exit cone through cooling holes in the basketliner. However, the single wall exit cone still experiences heatingdistress. Particularly, the cooling air supply provided to the coolingholes in the basket liner is split between the splash plate and the exitcone, where the splash plate typically receives the majority of thecooling air. It is difficult to control the separation of the coolingair to the exit cone and the splash plate, where the exit cone couldreceive reduced cooling and increased distress.

SUMMARY OF THE INVENTION

The present disclosure describes a combustor basket assembly for a gasturbine engine that includes a combustor basket having a basket linerincluding an input end and an output end. An integrated exit cone andsplash plate member is affixed to the output end of the basket liner andincludes a base portion, an exit cone portion and a splash plateportion. The base portion includes an annular cooling channel thatreceives a pressurized cooling air flow and the exit cone portion andthe splash plate portion each include an array of cooling feed holes influid communication with the cooling channel. The spacing between thefeed holes and the size of the feed holes can be optimized to providemore cooling for hotter regions.

Additional features of the present invention will become apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cut-away, isometric view of a gas turbine engine;

FIG. 2 is a cut-away, cross-sectional type view of a portion of a knowncombustion section for a gas turbine engine;

FIG. 3 is a cut-away, cross-sectional type view of an area at the end ofthe basket liner of the combustion section shown in FIG. 2;

FIG. 4 is a cut-away, isometric view of a portion of an output end of acombustor basket including a double-wall exit cone and splash plate;

FIG. 5 is a cut-away, isometric view of a portion of an output end of acombustor basket including an integrated exit cone and splash platemember; and

FIG. 6 is a cross-sectional view of the exit cone and splash platemember removed from the combustor basket.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following discussion of the embodiments of the invention directed toan integrated exit cone and splash plate member affixed to an output endof a combustor basket liner in a gas turbine engine is merely exemplaryin nature, and is in no way intended to limit the invention or itsapplications or uses.

FIG. 1 is a cut-away, isometric view of a gas turbine engine 10including a compressor section 12, a combustion section 14 and a turbinesection 16 all enclosed within an outer housing or casing 30, whereoperation of the engine 10 causes a central shaft or rotor 18 to rotate,thus creating mechanical work. The engine 10 is illustrated anddescribed by way of a non-limiting example to provide context to theinvention discussed below. Those skilled in the art will appreciate thatother gas turbine engine designs can also be used in connection with theinvention. Rotation of the rotor 18 draws air into the compressorsection 12 where it is directed by vanes 22 and compressed by rotatingblades 20 to be delivered to the combustion section 14, where thecompressed air is mixed with a fuel, such as natural gas, and where thefuel/air mixture is ignited to create a hot working gas. Morespecifically, the combustion section 14 includes a number ofcircumferentially disposed combustors 26 each receiving the fuel that isinjected into the combustor 26 by an injector (not shown), mixed withthe compressed air and ignited by an igniter 24 to be combusted tocreate the working gas, which is directed by a transition component 28into the turbine section 16. The working gas is then directed bycircumferentially disposed stationary vanes (not shown in FIG. 1) in theturbine section 16 to flow across circumferentially disposed turbineblades 34, which causes the turbine blades 34 to rotate, thus rotatingthe rotor 18. Once the working gas passes through the turbine section 16it is output from the engine 10 as an exhaust gas through an outputnozzle 36.

Each group of the circumferentially disposed stationary vanes defines arow of the vanes and each group of the circumferentially disposed blades34 defines a row 38 of the blades 34. In this non-limiting embodiment,the turbine section 16 includes four rows 38 of the rotating blades 34and four rows of the stationary vanes in an alternating sequence. Inother gas turbine engine designs, the turbine section 16 may includemore or less rows of the turbine blades 34. It is noted that the mostforward row of the turbine blades 34, referred to as the row 1 blades,and the vanes, referred to as the row 1 vanes, receive the highesttemperature of the working gas, where the temperature of the working gasdecreases as it flows through the turbine section 16.

FIG. 2 is a cut-away, cross-sectional type view of a portion of thecombustion section of a gas turbine engine having a similar design tothe gas turbine engine 10 and showing one of the combustors 26 and oneof the transition components 28. The combustor 26 includes a nozzlesection 40 through which the fuel is injected into a cylindricalcombustor basket 42 in a controlled manner as is well understood bythose skilled in the art. Air from the compressor section 12 enters thecombustor basket 42 through circumferentially disposed openings 44,where the air/fuel mixture is ignited by the igniter 24 (see FIG. 1) togenerate the hot working gas. The working gas flows through acylindrical basket liner 54 that defines an enclosure of the basket 42towards a basket exit 46 at an end of the basket 42 opposite to thenozzle 40.

FIG. 3 is broken-away, cross-sectional type view of a portion of theoutput end of the basket 42. An annular exit cone 80 is mounted withinthe basket liner 54 upstream from the basket exit 46 through which thehot working gas exits the basket 42. The end of the basket liner 54 isslid into a transition cylinder 52 having an annular mounting flange 48.A spring clip 84 is secured to an outside surface of the basket liner 54at the basket exit 46 and provides a spring force against the transitioncylinder 52 to hold the basket 42 within the transition cylinder 52.

The transition component 28 includes an annular flange 50 at an inputend that is mounted to the annular flange 48 of the transition cylinder52. The transition component 28 also includes a curved transitionsection 56 extending from the flange 50 that includes an inlet ringportion 58 and defining an internal chamber 62. An end of the transitionsection 56 opposite to the flange 50 includes a seal 64 and a mountingflange 66 through which the working gas is output to the turbine section16. The transition section 56 transitions from a circular opening at theinput end of the component 28 to a rectangular opening at the output endof the component 28. The mounting flange 66 is mounted to a ring bracket68 that is secured to a blade ring 70, all well known to those skilledin the art. The seal 64 of the transition section 56 is positionedadjacent to row 1 vanes 72 that receive and direct the hot gas to therow 1 blades. A mounting bracket 74 is mounted to the transition section56, as shown, and to a compressor exit diffuser 76.

Analysis has shown that the exit cone 80 creates a recirculation zonewithin the area between the exit cone 80 and the basket exit 46 thatcauses hot gas to be recirculated back towards the combustor basket 42and impinge a backside surface 86 of the exit cone 80. For the currentcombustor basket design, it is not possible to apply a thermal barriercoating (TBC) to the outer surface of the basket liner 54 including thebackside surface 86 of the exit cone 80 because that coating wouldinsulate basket components from cooling air provided to cool the basket42. In order to address this problem, it is known in the art to providean annular splash plate 90 mounted to the basket liner 54 within thebasket exit 46, but outside of the exit cone 80, as shown, that definesa cooling channel 92 therebetween. A series of spaced apart cooling feedholes 96 are provided through the basket liner 54 at the basket exit 46that receive cooling air flowing between the spring clip 84 and thebasket liner 54 and into the channel 92. Further, a series of spacedapart feed holes 100 are provided in the splash plate 90 that allow thecooling air flowing through the feed holes 96 to also flow through thesplash plate 90 and cool the exit cone 80. However, this creates aproblem because the cooling air is fed to the exit cone 80 by the samefeed holes that provide cooling flow to the splash plate 90, and thusthere is a reduction in the amount of cooling air that can be providedto the exit cone 80. This can be compensated for by increasing the sizeof the feed holes 96 and 100 for the cooling air, however, it isdifficult to control the cooling air that is split between the exit cone80 and the splash plate channel 92.

The present invention proposes solutions to this problem that allow allrelevant surfaces of the basket liner 54, the basket exit 46 and theexit cone 80 to be provided with a thermal barrier coating, and alsoallows a controlled amount of cooling air supplied to the exit cone 80and the splash plate 90.

FIG. 4 is a broken-away, isometric view of a portion of an output end ofa combustor basket 102 according to one proposed design, where likeelements to the discussion above are shown by the same reference number.In one design change, the exit cone 80 is replaced with a double-wallexit cone 110 including an inner cone wall 112 and an outer cone wall114 defining an annular channel 116 therebetween, where both of thewalls 112 and 114 are mounted to the basket liner 54 at the basket exit46, as shown. The outer cone wall 114 includes a barrier wall portion118 that engages an end of the splash plate 90 and the basket liner 54.Another design change includes providing an extended spacer ring 120mounted to an outside surface of the basket liner 54 at the basket exit46, where the spring clip 84 is secured to an outside surface of thespacer ring 120, as shown. The spacer ring 120 includes outer walls 122that define an enclosure and inner walls 124 that define a series ofparallel flow channels 126 within the enclosure. Cooling air flowingbetween the spring clip 84 and the basket liner 54 flows into andthrough the flow channels 126. In an alternate embodiment, the springclip 84 can be secured to the basket liner 54 farther upstream or downstream from the position shown, where the spacer ring 120 can beeliminated.

A series of spaced apart pairs of adjacent feed holes 130 and 132 areformed through the bottom wall of the spacer ring 120 and are alignedwith cooperating feed holes (not shown) in the basket liner 54. The feedholes 130 and 132 are positioned on opposite sides of the barrier wallportion 118 of the outer exit cone wall 114, where the holes 130 are influid communication with the channel 116 between the exit cone walls 112and 114, but not the channel 92, and the holes 132 are in fluidcommunication with the channel 92, but not the channel 116. The holes130 and 132 are properly metered, i.e., have a certain relative size, sothat the desired amount of cooling air is provided to the exit cone 110and the desired amount of cooling air provided to the splash plate 90,where the barrier wall portion 118 prevents the cooling air fromcombining. Thus, in this design, an outer surface of the exit cone wall114 and an inner surface of the exit cone wall 112 that are not exposedto the cooling air have a thermal barrier coating 134 and 136,respectively, that helps prevent those components from being burned bythe hot working gas. Also, a thermal barrier coating 82 is provided onan outer surface of the basket liner 54 at the exit 46.

The combustor basket 102 has been shown to be effective in providingcooling air to the relevant parts at the end of the combustor basket102. However, improvements can be made to this design so as to reducethe cost of the overall basket including reducing the part count,reducing the installation time, reducing the machining required,reducing the number of welds, etc. For example, because the parts arewelded together, the thermal expansion of the parts creates highstresses at the joints, which increases the possibility of failure. Thepresent invention proposes another embodiment that combines several ofthe parts at the output end of the combustor basket 102 as a singleintegrated piece so as to reduce the part count, manufacturingcomplexities, installation time, etc. This combination of componentsreduces the number of welds thus eliminating stresses caused by thewelds. This embodiment, as a result of individual cooling holes, alsoallows for circumferentially varying cooling, i.e., providing largerholes and closer pitch, which allows the cooling to be concentrated inhotter regions.

FIG. 5 is a broken-away, isometric view of a portion of an output end ofa combustor basket 140 according to this proposed design, where likeelements to the combustor basket 102 are shown by the same referencenumber. In this design, the double-wall exit cone 110, the splash plate90, the spacer ring 120 and the exit end of the basket liner 54 arereconfigured as an integrated single piece exit cone and splash platemember 142. FIG. 6 is a cross-sectional view of the exit cone and splashplate member 142 separated from the combustor basket 140. In thisdesign, the basket liner 54 is reduced in length and ends at annularliner edge 144, where the exit cone and splash plate member 142 includesa flange 146 that is welded to the liner edge 144. The exit cone andsplash plate member 142 can be fabricated using any metal suitable forthe purposes discussed herein, such as by forging, casting, etc.

The exit cone and splash plate member 142 includes a base portion 150,an exit cone portion 152 and a splash plate portion 154, where an angledtransition portion 148 is provided between the base portion 150 and thesplash plate portion 154. The transition portion 148 replaces the spacerring 120 and bridges the gap between the liner 54 and the spring clip84. The base portion 150 includes an annular flow channel 156 between anupper wall portion 158 and a lower wall portion 160 that extendscircumferentially around the exit cone and splash plate member 142. Theexit cone portion 152 includes a series of spaced apart cooling feedholes 162 in fluid communication with the channel 156 and the splashplate portion 154 includes a series of spaced apart cooling feed holes164 in fluid communication with the channel 156. The cooling airreceived by the channel 156 flows into the holes 162 and out an outputend 166 of the exit cone portion 152. Likewise, cooling air from thechamber 156 flows into the holes 164 and out an output end 168 of thesplash plate portion 154. The diameter, number, spacing, pitch, etc. ofthe feed holes 162 and 164 can be selected for an optimal coolingdesired for a particular gas turbine engine in combination with thepressure and flow of the cooling air, where the spacing between theholes 162 and 164 and the size of the holes 162 and 164 can be optimizedto provide more cooling for hotter regions.

As with the combustor basket 102 discussed above, a thermal barriercoating is provided on the surfaces of the exit cone and splash platemember 142 that do not receive the cooling air. Particularly, a thermalbarrier coating 170 is provided on an outer surface of the splash plateportion 154, a thermal barrier coating 172 is provided on an innersurface of the splash plate portion 154 and an outer surface of the exitcone portion 152, and a thermal barrier coating 174 is provided on aninner surface of the base portion 150 and an inner surface of the exitcone portion 152.

The foregoing discussion discloses and describes merely exemplaryembodiments of the present invention. One skilled in the art willreadily recognize from such discussion, and from the accompanyingdrawings and claims, that various changes, modifications and variationscan be made therein without departing from the scope of the invention asdefined in the following claims.

What is claimed is:
 1. A combustor basket assembly for a combustor in agas turbine engine, said combustor basket assembly comprising acombustor basket including a basket liner having an input end and anoutput end through which a hot working gas exits the combustor basket,said combustor basket further including a single piece exit cone andsplash plate member affixed to the output end of the basket liner, saidexit cone and splash plate member including a base portion, a splashplate portion integral with the base portion and an exit cone portionintegral with the base portion, where the hot working gas exits thecombustor basket through the exit cone portion.
 2. The combustor basketassembly according to claim 1 wherein the base portion includes acooling air chamber that receives a cooling air flow, the splash plateportion includes a plurality of cooling air feed holes that are in fluidcommunication with the chamber and receive cooling air therefrom, andthe exit cone portion includes a plurality of cooling air feed holesthat are in fluid communication with the chamber and receive cooling airtherefrom.
 3. The combustor basket assembly according to claim 2 whereina spacing between the feed holes and a size of the feed holes can beoptimized to provide more cooling for hotter regions.
 4. The combustorbasket assembly according to claim 2 wherein the cooling air chamber isan annular chamber that is circumferentially disposed around the member.5. The combustor basket assembly according to claim 1 wherein the exitcone and splash plate member is an annular member where the splash plateportion has a larger diameter than a diameter of the exit cone portion.6. The combustor basket assembly according to claim 1 further comprisingan annular spring clip mounted to an outer wall of the base portion,said spring clip allowing cooling air to flow to the base portion. 7.The combustor basket assembly according to claim 1 wherein an innersurface and an outer surface of the exit cone portion are coated with athermal barrier coating.
 8. The combustor basket assembly according toclaim 1 wherein an inner surface and outer surface of the splash plateportion are coated with a thermal barrier coating.
 9. The combustorbasket assembly according to claim 1 wherein the exit cone and splashplate member is welded to the output end of the basket liner.
 10. Anannular single piece exit cone and splash plate member operable to beaffixed to an output end of a basket liner associated with a combustorin a gas turbine engine, said exit cone and splash plate membercomprising a base portion, a splash plate portion integral with the baseportion and an exit cone portion integral with the base portion.
 11. Themember according to claim 10 wherein the base portion includes anannular cooling air chamber that receives a cooling air flow, the splashplate portion includes a plurality of cooling air feed holes that are influid communication with the chamber and receive cooling air therefrom,and the exit cone portion includes a plurality of cooling air feed holesthat are in fluid communication with the chamber and receive cooling airtherefrom.
 12. The member according to claim 10 wherein the splash plateportion has a larger diameter than a diameter the exit cone portion. 13.The member according to claim 10 wherein an inner surface and an outersurface of the exit cone portion are coated with a thermal barriercoating, and an inner surface and outer surface of the splash plateportion are coated with a thermal barrier coating.
 14. A gas turbineengine comprising: a shaft provided along a center line of the turbine;a compressor section responsive to a working fluid and being operable tocompress the working fluid to produce a compressed working fluid; acombustion section in fluid communication with the compressor sectionthat receives the compressed working fluid, said combustion sectionincluding a plurality of combustors that mix the compressed workingfluid with a fuel and combust the compressed fluid and fuel mixture toproduce a hot working gas, each combustor including a combustor basketassembly in which the combustion occurs, said combustor basket assemblycomprising a combustor basket including a basket liner having an inputend and an output end through which the hot working gas exits thecombustor basket, said combustor basket further including a single pieceexit cone and splash plate member affixed to the output end of thebasket liner, said exit cone and splash plate member including a baseportion, a splash plate portion integral with the base portion and anexit cone portion integral with the base portion, where the hot workinggas exits the combustor basket through the exit cone portion; and aturbine section in fluid communication with the combustion section, saidturbine section expanding the hot working fluid to produce mechanicalpower through rotation of the shaft.
 15. The gas turbine engineaccording to claim 14 wherein the base portion includes a cooling airchamber that receives a cooling air flow, the splash plate portionincludes a plurality of cooling air feed holes that are in fluidcommunication with the chamber and receive cooling air therefrom, andthe exit cone portion includes a plurality of cooling air feed holesthat are in fluid communication with the chamber and receive cooling airtherefrom.
 16. The gas turbine engine according to claim 15 wherein thecooling air chamber is an annular chamber that is circumferentiallydisposed around the member.
 17. The gas turbine engine according toclaim 14 wherein the exit cone and splash plate member is an annularmember where the splash plate portion has a larger diameter than adiameter of the exit cone portion.
 18. The gas turbine engine accordingto claim 14 further comprising an annular spring clip mounted to anouter wall of the base portion, said spring clip allowing cooling air toflow to the base portion.
 19. The gas turbine engine according to claim14 wherein an inner surface and an outer surface of the exit coneportion are coated with a thermal barrier coating.
 20. The gas turbineengine according to claim 14 wherein an inner surface and outer surfaceof the splash plate portion are coated with a thermal barrier coating.